iTunes freezing while Syncing

Every time I try to sync, iTunes freezes and appears the message "Finding Purchased items on XXX's iPad" It seems that this is related to iBooks and downloading content for it, such as the free Winnie the Pooh book. This apps checking for purchases will cause iTunes freeze on the computer.I plug in iPad and cancel sync. Then delete iBooks and Winnie the Pooh app. Now it works no problem.